Compressor rotor with anti-vortex fins

ABSTRACT

A compressor rotor of a gas turbine engine includes a rotor body having a face adapted to face an adjacent rotor. The rotor body extends radially between an outer peripheral rim surface and an inner rim surface. The inner rim surface defines a bore of the rotor body. A plurality of blades extends radially from the outer peripheral rim surface. A plurality of anti-vortex fins extends axially from the face of the rotor body facing the adjacent rotor. The plurality of anti-vortex fins forms a plurality of open radial passageways. The plurality of anti-vortex fins extends axially to a predetermined thickness such that, when assembled with the second rotor, axial extremities of the plurality of anti-vortex fins being in close proximity with the adjacent rotor and the adjacent rotor closes the radial passageways. A method of providing a first rotor for assembly with a second facing rotor of a compressor rotor assembly is also presented.

TECHNICAL FIELD

The present application relates to gas turbine engines and, moreparticularly, to anti-vortex structures in a compressor.

BACKGROUND OF THE ART

Conventional compressor bleed arrangements typically consist of arelatively complex assembly of parts, such as discs, plates, sheet metalguide vanes, conical members, shafts and rotors. All these parts arecumbersome and add to the overall weight and cost of the engine. Spacelimitations as well as the needs for not disrupting the airflow in themain gas path of the engine also render the installation of multi-partsbleeding arrangement challenging. Multi-part assemblies also suffer fromnon-negligible pressure drops notably at the joints between differentlyoriented parts. They may also affect the balance of the compressor rotorwhen mounted thereto.

SUMMARY

In one aspect, there is provided a compressor rotor of a gas turbineengine, the compressor rotor comprising: a rotor body having a faceadapted to face an adjacent rotor, the rotor body extending radiallybetween an outer peripheral rim surface and an inner rim surface, theinner rim surface defining a bore of the rotor body; a plurality ofblades extending radially from the outer peripheral rim surface; and aplurality of anti-vortex fins extending axially from the face of therotor body facing the adjacent rotor, the plurality of anti-vortex finsforming a plurality of open radial passageways, the plurality ofanti-vortex fins extending axially to a predetermined thickness suchthat, when assembled with the second rotor, axial extremities of theplurality of anti-vortex fins being in close proximity with the adjacentrotor and the adjacent rotor closes the radial passageways.

In another aspect, there is provided a compressor rotor assembly of gasturbine engine, the compressor rotor assembly comprising: first andsecond adjacent rotors, the first rotor including: a rotor body, therotor body having axially opposed faces, the rotor body extendingradially between an outer peripheral rim surface and an inner rimsurface, the inner rim surface defining a bore of the body; a pluralityof blades extending radially from the outer peripheral rim surface; aplurality of anti-vortex fins extending axially from the face of thefirst rotor facing the second rotor, the plurality of anti-vortex finsforming a plurality of radial passageways closed by the second rotor sothat the radial passageways are fluidly independent from each other.

In a further aspect, there is provided a method of providing a firstrotor for assembly with a second facing rotor of a compressor rotorassembly, the method comprising: i) forming a plurality of anti-vortexfins extending axially from a face of the first rotor at a predeterminedthickness such that, when assembled with the second rotor, axialextremities of the plurality of anti-vortex fins are in close proximitywith the second rotor and the plurality of anti-vortex fins definebetween the first rotor and the second rotor a plurality of fluidlyindependent radial passageways.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying figures in which:

FIG. 1 is a schematic cross-sectional view of a gas turbine engine;

FIG. 2 is a schematic cross-sectional view of a high pressure rotorassembly of the gas turbine of FIG. 1;

FIG. 3 is a schematic isometric view of a high pressure rotor of thehigh pressure rotor assembly of FIG. 2 according to a first embodiment;and

FIG. 4 is a schematic isometric view of a high pressure rotor of thehigh pressure rotor assembly of FIG. 2 according to a second embodiment.

DETAILED DESCRIPTION

FIG. 1 illustrates a gas turbine engine 10 of a type preferably providedfor use in subsonic flight, generally comprising in serial flowcommunication a fan 11 through which ambient air is propelled, amultistage compressor 12 for pressurizing the air, a combustor 13 inwhich the compressed air is mixed with fuel and ignited for generatingan annular stream of hot combustion gases, and a turbine section 14 forextracting energy from the combustion gases. The multi-stage compressor12 is herein shown in simplified view but comprises among others a lowpressure compressor rotor 15 followed by an assembly of high pressurerotors including a first axial compressor rotor 20 and an impeller 21.

With reference to FIG. 2, the impeller 21 is disposed downstream of therotor 20 relative to a flow of air flowing through a gas path 23. Thecompressor rotor 20 is supported by a high pressure engine shaft 25(shown in FIG. 1). The high pressure shaft 25 rotates with thecompressor rotor 20 in a direction of rotation Dr. The high pressureengine shaft 25 includes a central passage 26 which communicates withthe gas path 23. The compressor rotor 20 is designed to channel bleedair 28 which escapes from the gas path 23 via clearance 29 between thecompressor rotor 20 and the impeller 21, toward the central passage 26.Bleed air 28 may be used to cool components of the turbine section 14 orto feed bearing cavities.

With additional reference to FIG. 3, a first embodiment of thecompressor rotor 20 will be described. The compressor rotor 20 includesa generally circular rotor body 30 and a central bore 32. The centralbore 32 defines an inner peripheral rim surface 34. The rotor body 30also includes an outer peripheral rim surface 36 from which a pluralityof blades 38 extend radially. The rotor body 30 defines two opposedfaces 40, 42. The face 42 faces the impeller 21 and includes a pluralityof channelling structures 44 for channeling the bleed air 28 to thecentral passage 26.

The plurality of channelling structures 44 includes a plurality ofcircumferentially distributed anti-vortex fins 46 extending axially fromthe face 42 and radially from the central bore 32. The anti-vortex fins46 may be integrally formed on the face 42 using various manufacturingtechniques. For example, the anti-vortex fins 46 could be milled with alarge cutter. The formation of the anti-vortex fins 46 could beintegrated to the compressor rotor 20's forging operation.

The anti-vortex fins 46 define a plurality of radial open passageways 48which are closed by the presence of the impeller 21. The passageways 48are fluidly independent from one another (i.e. the passageways 48 areclosed or almost closed channels and do not or almost not communicatewith each other). Because the anti-vortex fins 46 have a predeterminedthickness T such that axial extremities 47 of the fins 46 are in closeproximity with a face 21 a of the impeller 21, the bleed air 28 ischanneled in the individual passageways 48 without interacting or withlittle interaction with the other passageways 48. The independence ofthe passageways 48 may prevent vortex or swirling formation which inturn may reduce pressure drop in the bleed air 28.

In one embodiment, the anti-vortex fins 46 extend from the central bore32 to an intermediate rim surface 50. The intermediate rim surface 50extends axially from the face 42 and is disposed radially between theinner rim surface 34 and the outer peripheral rim surface 36. Theintermediate rim surface 50 includes a plurality of circumferentiallydistributed openings 52 generally radially aligned with the clearance29. The openings 52 communicate the bleed air 28 to the individualpassageways 48 and represent inlets I of the passageways 48. Theopenings 52 may be sized to allow a desired amount of bleed air 28without depleting the gas path 23 to an unacceptable level. In theembodiment shown in FIG. 3, the openings 52 are windows in theintermediate peripheral rim surface 50. It is however contemplated thatthe openings 52 could be cut-outs. One opening 52 may be associated witha unique one of the passageways 48. It is however contemplated that eachpassageway 48 could have more than one opening 52 associated to it.

The anti-vortex fins 46 connect directly with the central bore 32 sothat ends of the anti-vortex fins 46 at the central bore 32 representoutlets O of the passageways 48. While the embodiment shown in thefigures shows that the anti-vortex fins 46 are extending directly fromthe central bore 32, it is contemplated that the anti-vortex fins 46could extend from a location close to the central bore 32. It is alsocontemplated that an additional intermediate peripheral rim surfacedisposed at proximity with the central bore 32 could have a plurality ofopenings defining the outlets of the passageways 48. It is alsocontemplated that a cavity 53 defined between the face 42, the impeller21, the outer peripheral rim surface 36 and the intermediate peripheralrim surface 50 could include a plurality of fins or other channellingstructures. While the anti-vortex fins 46 shown in the Figures provideuniformly circumferentially spaced-apart passageways 48, it iscontemplated that the passageways 48 could be spaced unevenly along acircumference of the rotor body 30.

The plurality of channelling structures 44 shown herein forms taperingpassageways 48 toward the central bore 32. The tapering may favorpressure in the bleed air 28 by providing converging channels toward theoutlets. It is however contemplated that the passageways 48 could not betapered toward the central bore 32.

Tie-rods openings 54 are located at a connection between the anti-vortexfins 46 and the intermediate rim surface 50. The tie rods openings 54receive each a corresponding tie-rod (not shown) that runs through therotors to clamp the rotor discs altogether. It is contemplated that thetie-rods openings 54 could be located elsewhere on the rotor body 30.

While the plurality of channelling structures 44 is being shown to beformed onto the face 42 of the rotor 20, it is contemplated that thechannelling structures 44 could instead be formed on the face 21 a ofthe impeller 21 facing the rotor 20.

When the compressor rotor 20 rotates, bleed air 28 is being drawn fromthe gas path 23 through the clearance 29 between the compressor rotor 20and the impeller 21. The clearance 29 runs circularly and air is beingdrawn radially therethrough. Passed the clearance the bleed air 28 iscontained in the cavity 53 between the outer peripheral rim surface 36and the intermediate rim surface 50. From there, the bleed air 28 entersthe passageways 48 through their corresponding openings 52. At thatpoint, the bleed air 28 is segmented into a plurality of channel flows.The segmentation may avoid formation of vortices between the compressorrotor 20 and the impeller 21. The bleed air 28 is drawn in thepassageways 48 from the openings 52 (i.e. inlets) to the central bore 32(i.e. outlets). Once reaching the central bore 32, the bleed air 28 maytravel in opposite directions, either upstream (see arrow 56 in FIG. 2)toward, for example, a seal or downstream (see arrow 58 in FIG. 2)through the shaft supporting the rotors toward, for example, the turbinesection 14.

Turning now to FIG. 4, a second embodiment of the compressor rotor 20′will be described. Features of the compressor rotor 20′ common to thecompressor rotor 20 will not be described in details again and will bearsame reference numeral but with a prime. The compressor rotor 20′includes a plurality of anti-vortex fins 46′ similar to the anti-vortexfins 46 except that they are curved. The anti-vortex fins 46′ may becurved in the direction of rotation Dr so as to form a plurality offluidly independent curved passageways 48′. The curved passageways 48′may have a curvature determined to further increase pressure in thebleed air 28 by taking advantage of the rotation of the compressor rotor20. The curved passageways 48′ may be tapered from the inlets to theoutlets.

The above described compressor rotors may reduce weight, cost andcomplexity associated with separate anti-vortex rings. Integratinganti-vortex fins to the compressor rotor may allow different designs ofthe fins, including curved fins, which may further reduce pressure lossin the bleed air.

The above description is meant to be exemplary only, and one skilled inthe art will recognize that changes may be made to the embodimentsdescribed without departing from the scope of the invention disclosed.Other modifications which fall within the scope of the present inventionwill be apparent to those skilled in the art, in light of a review ofthis disclosure, and such modifications are intended to fall within theappended claims.

The invention claimed is:
 1. A compressor rotor of a gas turbine engine,the compressor rotor comprising: a rotor body having a face adapted toface an adjacent rotor, the rotor body extending radially between anouter peripheral rim surface and an inner rim surface, the inner rimsurface defining a bore of the rotor body; a plurality of bladesextending radially outwardly from the outer peripheral rim surface; aplurality of anti-vortex fins extending axially from the face of therotor body facing the adjacent rotor, the plurality of anti-vortex finsforming a plurality of open radial passageways, the plurality ofanti-vortex fins extending axially to a predetermined thickness suchthat, when assembled with the second rotor, axial extremities of theplurality of anti-vortex fins being in close proximity with the adjacentrotor and the adjacent rotor axially closes the radial passageways; andan intermediate rim surface disposed on the face facing the adjacentrotor, the intermediate rim surface being disposed between the outerperipheral rim surface and the inner rim surface and connecting theplurality of anti-vortex fins, the intermediate rim surface defining aplurality of inlets connected in flow communication with respective onesof the plurality of radial passageways, the inlets receiving bleed airand directing it radially inwardly to the associated radial passageways.2. The compressor rotor of claim 1, wherein the plurality of radialpassageways extends to the inner rim surface.
 3. The compressor rotor ofclaim 1, wherein the radial passageways are disposed circumferentiallyspaced-apart.
 4. The compressor rotor of claim 1, wherein the radialpassageways are curved in a direction of rotation of the compressorrotor.
 5. The compressor rotor of claim 1, wherein the anti-vortex finsare integral to the rotor body.
 6. The compressor rotor of claim 1,wherein the radial passageways are tapered toward the inner peripheralrim surface.
 7. A compressor rotor assembly of gas turbine engine, thecompressor rotor assembly comprising: first and second adjacent rotors,the first rotor including: a rotor body, the rotor body having axiallyopposed first and second faces, the first face facing the second rotor,the rotor body extending radially between an outer peripheral rimsurface and an inner rim surface, the inner rim surface defining a boreof the body; a plurality of blades extending radially outwardly from theouter peripheral rim surface; a plurality of anti-vortex fins extendingaxially from the first face of the first rotor, the plurality ofanti-vortex fins forming a plurality of radial passageways closed by thesecond rotor so that the radial passageways are fluidly independent fromeach other; and an intermediate rim surface disposed on the first faceof the first rotor, the intermediate rim surface being disposed towardthe outer rim surface and connecting the plurality of anti-vortex fins,the intermediate rim surface including a plurality of inlets connectedin fluid flow communication to respective ones of the radialpassageways.
 8. The gas turbine engine of claim 7, wherein the pluralityof radial passageways extends to the inner rim surface.
 9. The gasturbine engine of claim 7, wherein the radial passageways are disposedcircumferentially spaced-apart.
 10. The gas turbine engine of claim 7,wherein the radial passageways are curved in a direction of rotation ofthe rotor.
 11. The gas turbine engine of claim 7, wherein the secondrotor is an impeller.
 12. The gas turbine engine of claim 6, wherein theradial passageways are tapered toward the inner rim surface.
 13. Amethod of providing a first rotor for assembly with a second facingrotor of a compressor rotor assembly, the method comprising: i) forminga plurality of anti-vortex fins extending axially from a face of thefirst rotor at a predetermined thickness such that, when assembled withthe second rotor, axial extremities of the plurality of anti-vortex finsare in close proximity with the second rotor and the plurality ofanti-vortex fins define between the first rotor and the second rotor aplurality of fluidly independent radial passageways; and ii) forming anintermediate rim surface on the first rotor, the intermediate rimsurface connecting the plurality of anti-vortex fins, the intermediaterim surface including a plurality of inlets in a one-to-one relationshipwith the plurality of radial passageways.
 14. The method of claim 13,wherein forming the plurality of anti-vortex fins comprises formingcurved anti-vortex fins so that the plurality of curved anti-vortex finsdefine between the first rotor and the second rotor a plurality offluidly independent curved radial passageways.
 15. The method of claim13, wherein forming the plurality of anti-vortex fins comprises formingtapered anti-vortex fins so that the plurality of anti-vortex finsdefine between the first rotor and the second rotor a plurality offluidly independent tapered radial passageways toward a center bore ofthe first rotor.
 16. The method of claim 13, wherein forming theplurality of anti-vortex fins comprises milling with a cutter theplurality of curved anti-vortex fins from the face of the first rotor.